Oil filtering apparatus



June 21, 1949. E. R. ROBERTSON v 2,473,727

OIL FILTERING APPARATUS Filed Feb. 18. 1944 5 Sheets-Sheet l WIMLOADEDYMVE m m; nw my VALVE l/ #fsm/crm I/vveNToR June 21, 1949. E. R, ROBERTSON 2,473,727

' QIL FILTERING APPARATUS 5 Sheets-Sheet 2 Filed Feb. 18, 194A` w ff 1.9

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June 21, 1949. E. R. ROBERTSON 2,473,727

OIL FILTERING APPARATUS Filed Feb. 18, 1944 v 5 Sheets-Sheet 5 fyi f5 w f.

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E. R. RoBERTSoN on.. FILTER'ING APPARATUS Jung 21, 1949.

5 Sheets-Sheet 4 Filed Feb. 18, 1944 P* w w m, y. ww r y i www Y .W H\\\\\\\ N N Q w w WQ w, I y 4 E f M ww M M l MW W M M w ER. ROBERTSON OIL FILTERING APPARATUS June 21, E949.

5 Sheets-Sheet 5 Filed Feb. 1B, 1944 Patented June 2l, 1949 Price 2,473,727 on. mL'ramNG APPARATUS Application February 18, 1944, Serial No. 522,930

. In Great Britain May 4, 1943 12 claims. 1

This invention relates to oil ltering apparatus and more particularlyT to iiltering apparatus for incorporation in the lubricating system of internal combustion engines.

Two methods of filtering the oil in the lubricating system of internal combustion engines are in general use, namely the full-ilow method of illtration and the by-pass method of filtration. In full-ow illtration all the oil circulated by the oil circulation pump is passed through a filter adapted to handle a l large amount of oil and known as a full-ow lter, all the filtrate passing to the parts to be lubricated. To prevent the parts to be lubricated from being starved of oil in the event of the full-dow lter clogging up, a relief valve (usually called a by-pass valve) is generally included in the filter, said valve, when a predetermined pressure is exceeded on the inlet side of the lter, opening to allow oil to by-pass the lter and to pass directly to the bearings or other parts to be lubricated. In by-pass filtration part of the oil circulated by the Aoil circulation pump passes directly to the parts to be lubricated and the remainder of the oil, usually to 10% of the totaloil circulated, passes through a iilter adapted to filter to a finer degree than a full-flow lter and known as a by-pass lter, the filtrate from the bypass lter passing directly to the engine sump or other reservoir. l-Since the sump is at relatively low pressure, it is usually necessary to include, either lon the inlet side or the outlet side of the by-pass filter, means, known as a restrictor, for preventing excessive flow of oil through the byvpass lter. Such a restrictor may conveniently be provided by a fitting having a suitably restricted passageway therethrough.

By-pa'ss illters are becoming increasingly in favour for the filtration of engine oil, and are very satisfactory under normal engine operating conditions. However, in the case where new engines are being run in and in other cases where a relatively large amount of fine foreign particles are apt to be present in the oil in the engine sump, there is the danger that such particles may be carried over to the engine bearings or other working parts to a harmful extent, since with a by-pass lter, only a portion of the oil circulated by the oil circulation pump is forced through the lter.

The principal object of this invention is to provide filtering apparatus which is adapted for either full-flow or by-pass filtration and which can be readily changed from one type of filtration to the other.

A more specific object of the invention is to pro- Y vide filtering a'pparatuswherein the insertion into filtering position of the appropriate filtering medium for either full-flow or by-pass filtration results in the means controlling the iiow of oil being automatically brought to the positions required for the desired type of filtration.

A still further object of the invention is the provision of a filter unit which is adapted to be incorporated in the lubricating system of internal combustion engines and which may be used for either full-flow or by-pass filtration.

Other objects and advantages of the present invention will be apparent from the following description read in conjunction with' the accompanying drawings, in which Fig. 1 shows diagrammatically one form of l- I tering apparatus in accordance with my invention;

Figs. 2 to 7 illustrate one form of filter'unit in accordance with my invention, the'lter being shown arranged for full-flow filtration, Fig. 2 being a side elevational view, Fig. 3 a top plan view,

Fig. 4 a longitudinal section taken on the line ll-t of Fig. 3, Fig. 5 an elevational viewof the iilter as seen from the left of Fig. 2, Fig. 6 a part sectional view taken on the line 6-6 of Fig. 3, and Fig. 'I a part sectional view taken on the line 'I-'i of Fig. 2;

Figs. 8 to 12 illustrate one form of iilter unit in accordance with my invention in which the valves are automatically set for the desired type of ltration, Fig. 8 being a top plan view, Fig. 9 a longitudinal sectional view taken on the line 9-9 of Fig. 8, showing a lter cartridge adapted for fulliiow filtration, Fig. 10 a part sectional view taken on the line lll-l0 of Fig. 8, and Figs. 11 and 12 v being part sectional views, similar to those of Figs.

9 and 10 respectively, illustrating the position of the valves with a cartridge adapted for by-pass filtration.

Each of the various forms of. oil filtering apparatus shown in the drawingscomprises a main oil passageway having a valve, and a secondary oil circuit shunted across the valve, the secondary circuit including an oil filter means and a twoway valve or other means arranged on the outlet side of the filter means whereby oil may be passed from the lter means either back to the main oil passageway or to a separate by-pass outlet passageway. l

f Referring. now to Fig. l., which shows diagrammatically one form of apparatus suitable for use in the lubricating system of engines,`the main oil passageway l forms part of the main oil circuit which leads from the engine sump 2 or other source of oil to the bearings 3 or'other parts to be lubricatedand which includes an oil circulation pump 4. A spring-loaded valve l is arranged in the main oil passageway I on the pressure side of the pump, the loading on the valve being such that, below a predetermined pressure in passageway on the inlet side of the valve, the valve is closed and when the predetermined pressure is exceeded the valve opens against the action of its spring. The nlter l, which is preferably of the type comprising an outer casing and an inner illter` cartridge, is included in a secondary circuit 1 shunted across the valve l, and a two-way valve 8 is included in said circuit on the outlet side of the iilter, so that oil from the illter may either pass back to the main oil passageway I and thence to the bearings 3, or throughI the separate by-pass outlet passageway 3 back to the sump 2.

If it be desired to operate the apparatus as a full-ilow illter, the two-way valve 8 is actuated to place the outlet from the illter l in communication with the main oil passageway I, as shown in the drawings, whereby the whole of the oil circulated by the pump 4 passes through the filter and thence to the bearings, the spring-loaded valve 5v opening should undue pressure develop in the shunt circuit 1 so that the illter is by-passed. When it be desired to change to by-pass nltration, the cartridge in the illter is changed for one adapted to filter to a finer degree and the two-way valve 8 is actuated to place the outlet from the filter 6 into communication with the by-pass outlet passageway 9. Due to the high resistance to oil ow oil'ered by the by-pass cartridge, the spring-loaded valve l, in operation of the engine. is held open against its spring so that most of the oil circulated by the pump 4 passes directly to the engine bearings 3 and only a fraction of the oil passes through the nlter t directly back to the engine sump.

A restrictor, indicated by the reference nu' meral I0, is advantageously included in the bypass outlet passageway 8 so that should, through inadvertence, a full-flow (low resistance) cartridge be inserted in the illter when the two-way valve 8 is set for by-pass operation, excessive flow of oil through the by-pass outlet passageway will be prevented. It will be understood that. should a by-pass (high resistance) cartridge be inadvertently inserted in the lter when the two-way valve is set for full-now operation, the valve 5 in the main oil passageway will open to allow oil to pass directly to the bearings.

The main oil passageway valve and the twoway valve or other means whereby oil from the illter may be passed either back to the main oil circuit or to the by-pass outlet passageway may be combined with the illter to form a unit, and one formvof such a unit is shown in Figs. 2 to 'I of the drawings.

Referring now to Figs. 2 to '1, the filter unit therein shown comprises a generally cylindrical container Il having an integral domed bottom wall I2 provided with a draining plug I3 and a centrally disposedy aperture through which extends the boss I4 of a closure cap I5 welded to wall I2 which is provided with strengthening ilutes I6. A tube I 1 having apertures I8 therein extends centrally through the container II and has its lower end welded or brazed to boss |4 and its upper end extending beyond the open upper end of the container. Supported by spring I9 surrounding boss I4 and the lower part of tube I1 is an annular packing member or washer on which seats a cylindrical iiiter cartridge 2|. The cartridge is co-axially arranged within container I I and has a diameter somewhat less than the internal diameter of container Il and also has a centrally disposed longitudinally extending tube 22having a greater diameter than the external diameter o! tube I1.

The top of the container I is closed by a cover member 23 in the form of a dome-shaped casting having a rim 24, the inner face of which is formed with an annular recess housinga packing member 25. The upper end of container I is urged tightly against packing member 25 to form a liquid-tight assembly by bolt 2B screwed into the upper end of tube |1 which extends through a co-axial bore in the cover member, the said bore having a diameter greater than the external diameter of tube I1, thereby forming an annular space 4| surrounding tube |1. An annular packing member 28 surrounding tube I1 is interposed between an annular boss 21 on the top cover member 23 and the top of cartridge 2| and the spring I9 seating surfaces so as to prevent passage of oil from the space outside cartridge 2| directly to the spaces surrounding tube I1. Integral with top cover member 23 is a flange 29 having boltreceiving apertures 30 whereby the illter may be secured to the desired support.

Extending transversely through ilange 29 and cover member 23 is an oil inlet passageway 3| and a full-ilow outlet passageway 32. and passageways 3| and 32 are connected by a third pas- 'sageway 33 which, below a predetermined pressure of oil in passageway 33, is closed by plunger valve 34 movable within valve chamber 35 screwed into the enlarged outer end of passageway 33. The plunger 34, which is open at its inner end, is urged by spring 31 against a stop provided by the split spring ring 36 and it will be understood that, when the oil'pressure in passageway 33 exceeds the predetermined value, the plunger is forced to the left against the action of the spring to allow oil to ilow from passageway 33 through a hole 38 in valve chamber 35 into the full-flow outlet passageway 32. Passageways 3|, 32, 33 form, in effect, a single valve-controlled main oil passageway.

A longitudinally extending passageway 39 (see Fig. 3) connects inlet passageway 3| with space 40 beneath the top cover member 23 and oil entering passageway 3| passes down through passageway 39 into the space surrounding cartridge 2|, whence it iiows through cartridge 2| and into tube 1 through holes I8. The oil flows upwardly through tube |1 into the annular space 4| through holes 42 in the upper part of tube I1.

Communicatingwith space 4| are a by-pass outlet passageway 43 which extends obliquely through ange 29 and cover member 23, and a transverse passageway 44, which intersects and communicates with the full-flow outlet passageway 32, the outer end of passageway 44 being closed by screw plug 45. Flow of oil from space 4| through the passageways 43 and 44 is controlled by interchangeable screw plugs 46 and 41 receivable in longitudinally extending sockets 48 and 49 which intersect passageways 43 and 44 respectively. The plugs 46 and 41 are of such length that, when arranged as shown in the drawings (see Figs. 4 and 6), the passageway 43 is closed and the passageway 44 is open and that, when the plugs are substituted one for the other, passageway 43 is open and passageway. 44 is closed. Passageway 39, space 4| and passageway 44 form a secondary oil circuit which includes filter cartridge 2| and which is shunted across valve 34 in the main oil passageway, these Iparts corresponding respectively to the secondary oil circuit 1 which urges packing members 2n and 28 against their includes the lter 8 and which is shunted acrossl valve 5 in the main oil passageway l in Figure 1.

The operation of the iilteris as follows. Assuming that it is desired to operate the lter as a full-flow filter, a cartridge adapted for full-flow filtration is inserted into container ll and the plugs 46 and 4l (which correspond to valve 8 in Figure 1) are inserted into sockets 48 and 49 respectively, as shown in Figs. 4 and 6. With this arrangement of the plugs, the by-pass outlet'passageway t3 (which corresponds to passageway E in Figure l) is closed and, with plunger 32 in its closed position, all the oil forced into inlet passageway 3 I passes through the ilter cartridge and through the full-iiow filter outlet passageway dit to the full-flow outlet passageway 32. It will be understood that, in the event of excessive pressure building up on the inlet side of the cartridge, the plunger 3d moves to its open position, thus allowing oil to pass directly from inlet passageway 3i to the full-flow outlet passageway 32 and thence to the bearings or other parts to be lubricated.

When it is Jdesired to change to by-pass iiltration, the cartridge is changed for one adapted for by-pass filtration and the plugs t6 and di are interchanged. With these positions of the plugs, oil flowing through the cartridge and into space lit passes to the by-pass outlet passageway 43, and the passageway te is closed. The pressure required to force ol through the lay-pass cartridge is such, however, that plunger 3d is forced to its open position, thus allowing part of the oil pumped into passageway 3i to ow directly to the full-flow outlet passageway t2 via passageway 33. A restrictor (not shown) (corresponding to the resistor l@ in Figure 1) is preferably included in the by-pass outlet passageway 63, or in the pipe connecting such passageway to the engine sump, to prevent excessive flow of oil through the iilter cartridge.

It will be seen from the above description of the filter shown in Figs. 2 to 7 that I have provided a compact iilter which is adapted to be incorpor'ated in the lubricating system of internal combustion engines and which is readily changeable from full-flow filtration to by-pass filtration, and vice versa. From the description of the apparatus shown in Fig. 1, it will be understood that,

should the plugs 46 and 41 be incorrectly posi- .i

tioned for the type of cartridge housed within the container ll, oil will still iiow through the fulliiow outlet passageway 32 and the bearings will not be starved of oil.

In acocrdance with an important feature of my invention a valve or valves controlling ow of oil from the filter means to the by-pass and full-flow outlet passageways is or are automatically brought to the position required for the desired type of ltration. For example, iiow of filtrate to the full-flow and by-pass outlet passageways may be controlled by suitably-positioned spring-loaded valves such that, on insertion of a full-flow cartridge into operative position in the filter unit, means on the cartridge actuate the said valves against their spring pressure to close the by-pass outlet passageway and open the passageway permitting filtrate to flow to the fulliiow outlet passageway, the said valves, when the iull-ow cartridge is withdrawn, moving under y construction. similar to the filter unit illustrated in Figs. 2 to 7, and in Figs. 8 to 12 like reference numerals are used to denote like parts.

Referring now to Figs. 8 to 12, the cover member 23 has longitudinally extending bores 60, 80,

which intersect passageways e3 and 64 respectively and which terminate respectively in narrow bores 5I, 5l, communicating with the space t@ beneath cover member 23. Mounted within bores 50, 6U are plunger valves 52, 62-having stems 53, G3 which extend into and beyond narrow bores 5I, 6i respectively. The plungers 52, 62 are urged downwardly by springs 5&3, 64 interposed between the plungers and screw closure plugs 55, respectively. The length of bores 56 and 6G is such that, when the plungers are in their lowermost position, plunger 52 is below the by-pass outlet passageway d3, which is thereby open to the flow of iiltrate, and plunger t2 closes the passageway dd, as seen in Figs. 1l and 12, which show the position of the plungers for by-pass filtration, 2i' indicating a cartridge adapted for by-'pass filtration.

The cartridge adapted for full-iiow filtration is provided with means which, when the cartridge is in operative position, engage the projecting ends oi the plunger stems 53. 63 and lift the stems and plungers to such positions that the plunger 52 closes the by-pass outlet passageway d3 and the plunger t2 opens the full-dow iilter outlet passageway ed. Thus, the full-iiow cartridge, which is indicated by the reference numeral 2l", may have an annular boss I0 secured to the top of the cartridge, the said boss serving to lift the plungers, S2 to the positions required for fulliiow filtration, as shown in Figs. 9 and 10. It will be understood that, when the full-flow cartridge 2l" is removed from container Il, the plungers 52, 62, under the action of springs 5 4, 66, automatically vmove to the positions shown in Figs. 11 and 12, i. e. the positions required for by-pass filtration and that the plungers remain in such position until such time as they are automatically moved to the position for full-ow filtration by the insertion of a full-flow cartridge such as 2l I claim:

1. Oil filtering apparatus adapted to be used for full-iiow or by-pass filtration, said apparatus comprising an oil inlet, a first oil outlet delivering oil to a part to be lubricated', a passageway communicating with the oil inlet and with the oil outlet, a spring loaded valve operative in response to returning oil from said reservoir to said oil inlet,

a second oil outlet delivering oil to said reservoir, a second passageway communicating directly with the said filtering circuit on the outlet side of the filter means and also communicating with the second oil outlet, and means controlling the flow of oil from the iilter means to the i'lrst and second passageways whereby the whole of suchV oil may be passed either to the iirst outlet or to the second outlet. l

2. A full-flow oil iilter unit comprising a casing, illter means housed within the casing, an oil inlet communicating with said filter means, a first oil outlet delivering oil to a part to be lubricated, means for receiving oil to be filtered through' said inlet and through the filter means to the outlet,A

a passageway connected in shunt across the filter means, a relief valve in said passageway, which permits the filter means to be by-passed when excessive pressure builds up across the 'filter means, a second outlet from the filter means, and means for diverting the total fiow of filtrate from the first outlet to the second outlet.

3. An oil filter unit comprising a casing. filter means housed within the casing, an oil inlet communicating with said lter means, a. first oil outlet delivering oil to a part to be lubricated, means for passing oil to be filtered through said inlet and through the filter means to the outlet, said means including a passageway on the outlet side of the filter means and a first outlet valve controlling fiow of filtrate through said passageway, a passageway shunted across the filter means, a relief valve in said second mentioned passageway that is adapted to be opened to allow oil entering the filter unit to pass directly to the outlet when the pressure across'the lter means becomes excessive, a second outlet, a passageway connecting the second outlet with the outlet side of the filter means, a'nd a second outlet valve controlling fiow of filtrate through said third mentioned passageway, whereby said outlet valves may be selectively opened to eect operation of the filter unit alternately as a full-flow and bypass filter.

4. A unit according to claim ,3, wherein the filter means and the outlet valves are provided with cooperating control means comprising plugs of different length operable on insertion of said filter means in said casing to open one only of said valves and thereby to eiiect selection of fullfiow or by-pass operation.

5. A unit according to claim 3, wherein the outlet valves controlling the first and third mentioned passageways comprise plugs of different lengths housed in bores, one of which intersects one of said passageways, the said plugs being interchangeable and adapted one to close the first passageway and leave open the third passageway and the other to closev the third passageway and leave open the first passageway.

6. A unit according to claim 3, wherein the outlet valves controlling the first and third mentioned passageways are mounted in said casing and comprise spring urged plungers having projecting means positioned to extend across passageways and through a portion of the casing into a filtering chamber for engagement by the filter means on insertion of the latter in said casing, whereby' the plungers are held against their springs in operative position for full flow filtration, the plungers, when the filtering means is withdrawn from the casing, vbeing adapted to move under the action of their springs into operative position for by pass filtration.

7. An oil filter adapted for selective operation as a full-flow or a by-pass filter, comprising a casing, filter means housed within said casing, means for receiving oil to be filtered and delivering it to the filter, a first oil outlet delivering oil to a part to be lubricated, a passageway for by- .passing said filter means, a spring-controlled valve therein adapted to be opened whe-n the pressure becomes excessive, valve control means adapted when in one position to pass all the oil passed into the casing through the filter means to the outlet, a second outlet, said valve control means adapted when in a different position to pass part of the oil passed into thecasing partly through the filter means to the second outlet and the remainder of the oil separately and directly through the by-pass passageway to the first outlet.

8. In a, full-flow oil filter unit o! the type comprising a casing, filter means housed within the casing, means for receiving oil to be filtered and delivering it to the filter, said casing having a first oil outlet delivering oil to a part to be lubricated, means for passing oil to be filtered through the filter means to the outlet, a passageway shunted across the filter means and a valve in said passageway which is normally shut but is adapted to open when pressure across the filter means exceeds a certain value, said casing having a second outlet, a passageway placing the second outlet in communication with the outlet side of the filter means, and means for controlling the flow of filtrate such that the whole of the filtrate may be passed alternately to the first and second outlets.

9. An oil filter unit comprising a casing, filter means housed within said casing, a closure member for said casing having an oil inlet for connection to a source of supply of oil, a first oil outlet delivering oil to a part to be lubricated, a second outlet for returning oil to said source of supply, a passageway in said closure member connecting said inlet and the first outlet, a relief valve in said passageway adapted to open when the pressure on the inlet side thereof exceeds a predetermined value, means placing the passageway on the inlet side of the valve therein in communication with the inlet side of the filter means, a second passageway placing the first passageway on the outlet side oi' the valve therein in communication with the outlet side of the filter means, a third passageway placing the second outlet in communication with the outlet side of the filter means, and selectively operable control valves in the second and third passageways controlling the flow of filtrate therethrough whereby the filter unit may be used alternately for fullflow and by-pass filtration.

10. An oil filter unit according to claim 9, wherein the said control valves are in the form of interchangeable plugs, one of' which is adapted to close the second'passageway and open' the third passageway and the other of which is adapted to open the second passageway and to close the third passageway.

l1. An oil filter unit comprising a casing, said casing being constructed to receive and house a removable filter cartridge a first oil outlet on the unit delivering oil to a part to be lubricated, means for passing oil to be filtered through the filter cartridge to the outlet, a pressure release circuit connected in shunt across the filter cartridge permitting oil to be filtered to pass directly to the outlet when the pressure required to force oil through the lter cartridge exceeds a certain value, a source of supply of oil for said unit, a second outlet on the unit for connection to said supply source, means placing the outlet side of the filter cartridge in communication with the second outlet, spring-urged valve means controlling the flow of nitrate to the first and second outlets, said valve means being adapted to be moved against its spring action to a position in which filtrate may flow to the first outlet and not to the second outlet and to be moved under its spring action to a position in which filtrate may flow to the second outlet and not to the nrst outlet, said valve means being positioned for engagement by said cartridge to hold said valve means in the first mentioned position.

12. An oil filter unit comprising a casing, a

aereas? lter cartridge in said casing, a niet oil outlet delivering oil for to a part to be lubricated. means for passing oil to be ltered through the cartridge to the outlet, a passageway connected in shunt across the cartridge', a valve in said passageway whici is normally shut but which is adapted to open when the preure required to. force oil.l

value, a second outlet, a second passageway placing the second outlet in communication with the outlet side of the cartridge, valve lmeans controlling ow of ltrate from `the cartridge and adapted, in one position, to allow nitrate to ow only to the first outlet and, in another position,

to allow ltrate to flow only to the second outlet,

and means on the cartridge engaging the valve means to hold them in a selected one ot auch WARD nonna Roann'rson. 1

vthrough the cartridge exceeds a predetermined I i REFERENCES CITED 

